Illuminated typewriter platen



March 8, 1955 c. H. MINOGUE ETAL ILLUMINATED TYBEWRITER PLATEN Filed April 26, 1952 g INVENTORS.

%Zm f f 2 United States Patent ILLUMINATED TYPEWRITER PLATEN Curtis H. Minogue and William F. Kottmeyer, Chicago, Ill.

Application April 26, 1952, Serial No. 284,546

Claims. (Cl. 240-2) This invention relates to a typewriter or typewriting machine, and more particularly to a platen therefor.

The cutting of a stencil sheet for mimeographing purposes with a typewriting machine has long been a common practice. In instances, however, where the mimeographed sheet is to include one or more pictorial representations thereon, as well as typewritten matter, it frequently becomes a difficult, awkward, and time-consuming operation to properly align the typewritten matter with respect to the pictorial representation. It is likewise difficult to correct stencil sheets that have already been inked on the duplicating or mimeographing machinefor example, after the stencil sheet has been run on the machine and discovery is made that a correction of the stencil sheet is required. To effect such a correction on an ordinary typewriter platen is extremely difiicult because the vision of the characters or printed matter on the stencil sheet is materially impaired because of the ink which has been applied to the sheet.

Various attempts have heretofore been made to alleviate or overcome this difficulty by the use of either an illuminated or a self-illuminating platen. Illuminated platens, however, have not been successful because of the failure to provide effective illumination at the required location. The self-illuminating platen, while an improvement over the illuminated type, has had certain shortcomings such as failure to provide uniform light intensity through the length of the platen, want of effective heat dissipation, costly and complex construction, and difficulty in installing on the conventional style machines. Further disadvantages with prior self-illuminating platens resided in the fact that certain operating features of the machine had to be sacrificed in order to accommodate such a platen, and also the means of introducing the leads for the light-emitting element into the interior of the platen without binding or excessive twisting thereof was not successfully met.

Thus, it is one of the objects of this invention to provide a self-illuminating platen which overcomes the shortcomings and disadvantages of prior platens of this type, above enumerated.

It is a further object of this invention to provide a self-illuminating platen which is simple and inexpensive in construction, elfective in operation, and may be readily installed in a new machine or one presently in use without necessitating extensive modification or sacrificing of any of the operational features of the machine.

Further and additional objects will appear from the description, accompanying drawings and appended claims.

In accordance with one embodiment of this invention, a platen for a typewriting machine is provided comprising an elongated rotatably mounted hollow member constructed of light-transmitting material and light-emitting means mounted within said hollow member for emitting light rays of substantially uniform intensity throughout said member.

For a more complete understanding of this invention, reference should now be made to the drawings, wherein:

Figure 1 is a fragmentary perspective view of a typewriting machine showing the improved platen mounted thereon;

Fig. 2 is a fragmentary sectional view of the improved platen; v

Figs. 3, 4, and 5 are sectional views taken along lines 3-3, 4-4, and 5-5, respectively, of Fig. 2;

2,703,836 Patented Mar. 8, 1955 Fig. 6 is a fragmentary sectional view of one end of a modified form of platen;

Fig. 7 is a fragmentary sectional view taken along line 77 of Fig. 6; and

Fig. 8 is similar to Fig. 4 but showing still another modified form of platen.

Referring now to the drawings, and more particularly to Fig. 1, a conventional style or standard form of typewriting machine 10 is shown comprising a carriage 11 which is mounted for movement transversely relative to a stationary housing 12. The carriage 11 comprises a pair of spaced platen-supporting members 13 which are adapted to engage the ends of the platen 14 and allow the latter to be rotated independently of the members. The platen 14 may be rotated manually by the operator either pivoting the forwardly projecting lever 14 or turning one of the pair of knurled knobs 15 which are mounted at opposite ends of the platen.

One form of the improved platen 14 is shown more clearly in Figs. 2 through 5 and comprises an elongated inflexible hollow member or sleeve 16 which is constructed of either a transparent or translucent material. The sleeve 16 is of sufiicient thickness to withstand the shock of the type striking thereagainst without the formation of cracks and the like. Secured to opposite ends of the sleeve 16 by means of screws 17, or any other suitable means, are a pair of bearing units 18a and 18b. Bearing unit 18b is of a type used on the conventional typewriter platen and the construction thereof is believed well understood by those skilled in the art.

Bearing unit 18a, on the other hand, differs considerably from uni-t 18b, see Fig. 2, and comprises a relatively thick washer 20 and a bushing member 21 secured to the exposed face thereof. The outside diameter of the washer in this instance is slightly less than the inside diameter of the sleeve 16 so that when the fastening screws 17 are withdrawn, the sleeve and bearing unit may be moved relative to one another. The bushing 21 is provided with an elongated hollow shank portion 22 which is disposed axially with respect to the longitudial axis of the sleeve 16. The shank portion 22 of the bushing 21 is rotatably mounted within a bearing sleeve 23 aflixed to the supporting member 13. To the end of shank portion 22 is secured by means of a lock screw, one of the knurled knobs 15, so that the knob and bushing 21 will rotate as a unit. Disposed within shank portion 22 is a conduit or pipe section 24 which is held in a fixed non-rotating position relative to bushing 21 by a brace 25. Brace 25 is rigidly secured to member 13 of the carriage and has one end thereof secured directly to the exposed end of pipe section 24. The inner end of pipe section 24 projects through bushing 21 and washer 20 and terminates within the interior 25 of hollow sleeve 16 at a point spaced from the inner surface of washer 20. Secured to the inner end of pipe section 24 by means of a holding screw 29 or any other suitable means is an elongated bracket 28. The bracket 28 is adapted to support a lightemitting element which, in this instance, comprises a fluorescent bulb 26 and electrical fixtures or sockets 27a and 27b therefor. The fixtures 27a and 27b are fastened 111 spaced relation on bracket 28 so as to hold the bulb 26 in position substantially equidistant from the ends of the sleeve 16. The fixtures 27a and 27b are of conventional construction and believed well understood by those skilled in the art.

The length of the bulb 26 may be varied according to the longitudinal length of the platen so that the light rays emitted from the bulb will be of substantially uniform intensity throughout the sleeve 16. As seen in Fig. 3, the bulb 26 is positioned at approximately 45 degrees to the vertical, thereby directing the illumination more effectively toward the operator. Where it is desirable to increase the effectiveness of the illumination toward the operator, a reflector 33 may be utilized, see Fig. 8, which is substantially the same length as the bulb 26. The reflector 33 is disposed between the bulb and bracket 28 and secured by rivets 34 or any other suitable means to the latter; the reflector is of such configuration as to direct the light rays to a predetermined portion of the sleeve periphery.

The electrical leads 30 for the fixtures 27a and 27b are introduced into the interior of sleeve 16 through pipe section 24. The outer ends of the leads are connected to a suitable source of electrical energy, not shown. Sleeve 16 is provided with a plurality of symmetrically arranged ports 31 disposed adjacent either bearing unit 18a or 18b so as to effectively dissipate any heat which might develop within the sleeve 16.

In instances where noise is an important consideration, a gasket 32 formed of cork, felt, rubber, or any other sound damping material may be inserted between the sleeve and the outside periphery of the washer 20, see Figs. 6 and 7.

When it is necessary to replace the bulb 26, the following procedure is suggested:

(a) The screws 17 which secure the sleeve 16 to the bearings units 18a and 18b are removed,

(b) The brace 25 is removed from the end of pipe section 24,

(c) Knob 15 is disconnected from pipe section 24,

(d) Pipe section 24 is pushed into sleeve 16 as far as possible and sleeve 16 is moved in the opposite direction until it abuts supporting member 13, at which point the opposite end of sleeve 16 is clear of heating unit 18b,

(e) The sleeve 16 and pipe section 24 are then pivoted upwardly about bearing unit 18a as an axis until sleeve 6 may be removed endwise free and clear of bearing unit 18b,

(f) The bulb 26 is then exposed and may be readily removed from the fixtures 27a and 27b.

To reassemble the platen, the above described procedure is reversed.

Thus it will be seen that a self-illuminating platen has been provided which provides uniform light intensity throughout the length of the platen, is simple and inexpensive in construction, effectively dissipates any heat which might develop within the platen, and may be readily installed in new machines or those presently in use.

While several embodiments of this invention are shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made.

We claim:

1. A device for use with a typewriting machine having a stationary base and a carriage mounted on said base for reciprocatory movement relative thereto, said device comprising an elongated hollow platen against which typewriter type carried by the base are caused to strike, said platen being mounted at opposite ends on the carriage and movable therewith for selective rotation independently thereof about the platen longitudinal axis to various predetermined positions, said platen having an annular peripheral section constructed of shock-resistant light-transmitting material, and a non-rotating light-emitting element mounted within said platen and spaced from the interior surface thereof and disposed adjacent said annular peripheral section.

2. A device for use with a typewriting machine having a stationary base and a carriage mounted on said base for reciprocatory movement relative thereto, said device comprising an elongated hollow platen against which typewriter type carried by the base are caused to strike, said platen being mounted at opposite ends on the carriage and movable therewith for selective rotation independently thereof about the platen longitudinal axis to various predetermined positions, said platen having an annular peripheral section thereof constructed of shockresistant light-transmitting material, light-emitting means disposed within said platen and in spaced relation with respect to the interior surface of said annular peripheral section for emitting, when energized, light rays of substantially uniform intensity throughout said platen annular peripheral section, and non-rotating energy-transmitting means having a portion thereof disposed within the interior of said platen and operatively connected to said light-emitting means for effecting energization of the latter and having a second portion extending outwardly from one end of said platen in a direction coaxial with respect to the axis of rotation of said platen.

3. A device for use with a typewriting machine having a stationary base and a carriage mounted on said base for reciprocatory movement relative thereto, said device comprising an elongated hollow platen against which typewriter type carried by the base are caused to strike, said platen being mounted on the carriage and movable therewith for selective rotation independently thereof about the platen longitudinal axis to various predetermined po sitions, said platen including an elongated center cylindrical section constructed of shock-resistant light-transmitting material and a pair of bearing sections, one being detachably secured to each end of said center section and being rotatably supported by the carriage on which the device is mounted, a light-emitting element mounted substantially centrally within said center section and adapted, when energized, to emit light rays of substantially uniform intensity throughout said center section, a non-rotating element-supporting fixture having a portion thereof disposed within the interior of said center section and contacting said light-emitting element and a second hollow portion being supported by and extending axially through one of said bearing sections, and non-rotating energy-transmitting means mounted on and extending through the second portion of said fixture and terminating at said light-emitting element for effecting energization thereof.

4. A device for use with a typewriting machine having a stationary base and a carriage mounted on said base for reciprocatory movement relative thereto, said device comprising an elongated hollow platen against which typewriter type carried by the base are caused to strike, said platen being mounted on the carriage and movable therewith for selective rotation independently thereof about the platen longitudinal axis to various predetermined positions, said platen including an elongated cylindrically shaped center section constructed of shock-resistant light-transmitting material having vents formed adjacent one end thereof and a pair of bearing sections detachably secured to opposite ends of said center section and being rotatably supported by the carriage on which the device is mounted, sound absorbing means mounted intermediate said bearing sections and the adjacent end portions of said center section, and non-rotatable lightemitting means mounted substantially centrally within the center section of said platen and spaced from the interior surface thereof for emitting, when energized, light rays of substantially uniform intensity throughout said center section.

5. A device for use with a typewriting machine having a stationary base and a carirage mounted on said base for reciprocatory movement relative thereto, said device comprising an elongated hollow platen against which typewriter type carried by the base are caused to strike, said platen being mounted on the carriage and movable therewith for selective rotation independently thereof about the platen longitudinal axis to various predetermined positions, said platen having an annular peripheral section constructed of shock-resistant light-transmitting material, an elongated light-emitting element disposed within said platen section, a non-rotating element-supporting fixture mounted at one end of said platen and extending into the section of said platen constructed of light-transmitting material, a reflector piece disposed within said platen section and mounted on said fixture and cooperating with said light-emitting element for substantially directing the light rays emitted from said element to a predetermined portion of the periphery of said platen section.

References Cited in the file of this patent UNITED STATES PATENTS 1,499,582 Laguionie July 1, 1924 2,351,251 Davenport June 13, 1944 2,431,520 Streich Nov. 25, 1947 2,453,931 Phillips Nov. 16, 1948 2,493,829 Paul Jan. 10, 1950 2,529,279 Breisch Nov. 7, 1950 2,559,159 Hruby July 3, 1951 2,567,049 Belluche Sept. 4, 1951 2,615,266 Wallin et al Oct. 28, 1952 

